As shown in FIGS. 4 and 5, there has been used seat material 5 having a covering member 6 integrally provided on foamed material for application to a seat cushion 2 or a seat back 3 of a car seat 1. The seat material 5 has a patterned portion 9 formed on a side face or a main or top face thereof by recessing the covering member 6 in a stripe pattern.
Such seat material 5 has been produced by using a foaming mould 11 as shown in FIG. 6. The foaming mould 11 comprises a lower mould half 12 and an upper mould half 13. The lower mould half 12 has a patterning protrusion 14 formed thereon and the covering member 6 is disposed within the lower mould half 12 so that a portion 7 of the covering member 6 to be patterned which may be of a sewed portion of the covering member 6 is engaged with the patterning protrusion 14 of the lower mould half 12. In this case, the covering member 6 should be secured to the patterning protrusion 14 of the lower mould half 12 by means of both face or double-sided adhesive tape so that the covering member 6 is never displaced out of the proper position. Resin material to be foamed is poured into the lower mould half 12 so that it is filled in the covering member 6 and then the lower mould half 12 is closed by the upper mould half 13 so that the resin material is foamed and cured. Thus, the seat material 5 is produced having foamed material 8 and the covering member 6 having the patterned portion 9 formed by recessing the covering member 6 in a stripe pattern by the patterning protrusion 14 of the lower mould half 12.
However, it has been difficult to positively secure the covering member 6 to the patterning protrusion 14 of the lower mould half 12 when the seat material 5 is produced. When the covering member 6 is secured to the patterning protrusion 14 of the lower mould half 12 by means of the both face or double-sided adhesive tape, if the covering member 6 is displaced, then it has to be removed from the both face adhesive tape and then resecured to the patterning protrusion 14 of the lower mould half 12, which causes the operation to be troublesome. In addition thereto, the surface of the covering member 6 is sometimes contaminated by the both face or double-faced adhesive tape. If the both face adhesive tape is not used, then the covering member 6 will float on the patterning protrusion 14 in the lower mould half 12, which disadvantageously causes the desired patterned portion 9 of the seat material 5 to be never obtained.